Numbers 121. Report of Colonel James Barnes,

Eighteenth Massachusetts Infantry, of operations June 26-July 2.

HDQRS. EIGHTEENTH MASSACHUSETTS REGIMENT,
In Camp at Harrison's Landing, on James River, Va., July 5, 1862.

SIR: In accordance with instructions received from you I have the honor to make the following statement of the duty performed by this regiment since Thursday last, the 26th day of June:

Very late on Wednesday evening, the 25th, while in camp at Gaines' Hill, I received orders to report to Brigadier-General Stoneman, of the cavalry, for special duty early on the following morning. I accordingly reported to him, and was instructed to report to him at an early hour in the morning at or near Old Church, equipped in light marching order, and by way of the Mechanicsville turnpike. The men were to by furnished with three days' provisions in their haversacks. An extra supply of ammunition was to be carried in a wagon and a supply of medical stores and ambulances. I accordingly started at 4.30 o'clock in the morning with an entire force of 514 officers and men, one ammunition wagons, one hospital transport, and two ambulances, the men furnished with the required provisions, and without other incumbrance than their blankets. The sick and others unfit for the arduous duty that was to be performed were left behind, who, together with the camp guard and others detailed for special duty, amounted in all to 238; these, with the portion taken with me, constituting the entire regiment. All the knapsacks and other property of the regiment were left in the camp.

Proceeding by the Mechanicsville turnpike, I reached that village and found everything apparently quiet. Passing thence by the old Hanover road toward Old Church, nothing particular occurred until arriving at the point where the road turns off to Old Church. I found General Emory in charge of a body of cavalry and artillery, and a good deal of excitement existing on account of the rumors that the enemy were likely soon to be in our rear. Under his instructions I moved rapidly forward toward Old Church, accompanied by a section of Captain Gibson's battery. We soon reached the place, and the battery and the part of the regiment assigned for its support were at once placed in position, the remainder being held in reserve.

In the mean time heavy firing was heard upon our left toward Mechanicsville, the point from which we had so recently arrived, and the approach of the enemy was eagerly looked for. After waiting in this position for some time and no force appearing, the firing in the mean time ceasing, I received instructions from General Stoneman to leave four companies as a support to the artillery and to withdraw the remainder of the regiment to the rear about half a mile on the opposite side of a small creek, which I did just after dark, and bivouacked for the night. During the night two additional companies were established as a picket to the left of our position. Nothing further transpired that night. The regiment was under arms at early dawn, and at a later period the pickets from the front and left were drawn in and the entire force under General Stoneman was withdrawn about a half mile to the rear, the four companies before spoken of acting as a rear a guard of the column, under the direction of Major Hayes. Here the whole force